Backlight assembly, display device having the same, display substrate for the same and method of manufacturing the same

ABSTRACT

A backlight assembly includes first and second backlight units independently operating based on driving modes, and a light blocking member interposed between the first and second backlight units. The first backlight assembly includes a first light source generating and supplying a first light to a main display part of a display panel in a main mode and turned-off in a sub mode. The second backlight assembly includes a second light source generating and supplying a second light having different color from the first light to a sub display part of the display panel in a main mode and a sub mode.

The present application claims priority to Korean Patent Application No.2005-63388, filed on Jul. 13, 2005, Korean Patent Application No.2005-65312, filed on Jul. 19, 2005, and Korean Patent Application No.2005-70713, filed on Aug. 2, 2005, and all the benefits accruingtherefrom under 35 U.S.C. §119, the contents of which is herebyincorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a backlight assembly, a display devicehaving the backlight assembly, a display substrate for the displaydevice and a method of manufacturing the display substrate. Moreparticularly, the present invention relates to a backlight assemblycapable of decreasing a power consumption, a display device having thebacklight assembly, which is capable of improving image display quality,a display substrate for the display device and a method of manufacturingthe display substrate.

2. Description of the Related Art

A liquid crystal display (LCD) device, in general, is used for personalcomputers, notebook computers, automobile navigation systems, televisionreceiver sets, etc. The LCD device converts an electric signal havingimage information into an image. The LCD device has variouscharacteristics such as a light weight, a small size, a thin thickness,a low power consumption, etc., so that the LCD device has been widelyused.

In a mobile LCD device, a display panel of the LCD device is dividedinto a main display part and a sub display part to improve opticalcharacteristics and to decrease power consumption. For example, the subdisplay part constantly displays auxiliary information such as time,data, battery state, etc. The main display part selectively displaysmain information such as image of a camera, character, etc.

The main display part and the sub display part of the LCD device receivea light generated from a same light source. The main display partdisplays the image in a main driving mode, and the main display partdoes not display the image in a sub driving mode. In the sub drivingmode, the light generated from the light source is incident into themain display part, but the main display part is turned off so that theimage is not displayed by a black driving of the main display part ofthe display panel.

In the sub driving mode, the light incident into the main display partis unnecessary. Therefore, in order to decrease a power consumption ofthe LCD device, a current of the sub driving mode has a smaller amountthan that of the main driving mode. However, when the amount of thecurrent of the sub driving mode is decreased, a luminance of the lightincident into the sub display part is decreased, thereby deterioratingan image display quality of the sub display part.

In addition, when the luminance of the backlight assembly is increasedin order to improve the image display quality, the power consumption ofthe backlight assembly is also increased.

The LCD device having the main and sub display parts includes a colorfilter for displaying a color image. The color filter transmits a colorlight to display the color image based on the light generated from thebacklight assembly. The color filter includes red, green and bluecolorants. The red, green and blue colorants block a portion of thelight generated from the backlight assembly, thereby decreasing aluminance of the LCD device. Therefore, in the sub driving mode, theluminance of the LCD device is greatly decreased by the decreased powerconsumption and the absorption of the light by the colorant, therebydeteriorating the image display quality of the sub display part.

BRIEF SUMMARY OF THE INVENTION

An exemplary embodiment provides a backlight assembly having lightsources in main and sub regions, which is capable of decreasing powerconsumption.

Another exemplary embodiment provides a display device having theabove-mentioned backlight assembly, which is capable of improving imagedisplay quality.

Another exemplary embodiment provides a display substrate for theabove-mentioned display device.

Another exemplary embodiment provides a method of manufacturing theabove-mentioned display substrate.

Another exemplary embodiment provides a display device having theabove-mentioned display substrate, which is capable of improving animage display quality at a low current.

One exemplary embodiment of a backlight assembly includes a firstbacklight unit, a second backlight unit and a light blocking member. Thefirst backlight unit supplies a main display part of a display panelwith a first light in a main mode and is turned off in a sub mode. Thesecond backlight unit supplies a sub display part of the display panelwith a second light in both of the main mode and the sub mode. The lightblocking member is interposed between the first and second backlightunits to prevent a light leakage of the first light from the firstbacklight unit to the second backlight unit and a light leakage of thesecond light from the second backlight unit to the first backlight unit.

Another exemplary embodiment of a backlight assembly includes a lightsource unit and a light guiding unit. The light source unit includes afirst light source and a second light source. The first light sourcegenerates a first light. The second light source generates a secondlight having a different color from the first light. The light guidingunit guides the first and second lights generated from the light sourceunit.

An exemplary embodiment of a display device includes a display panel, abacklight assembly and a driving circuit part. The display panelincludes a main display part and a sub display part. The main displaypart selectively displays a main image. The sub display part constantlydisplays a sub image. The backlight assembly includes a first backlightunit and a second backlight assembly unit. The first backlight unitsupplies the main display part with a first light. The second backlightunit supplies the sub display part with a second light. The drivingcircuit part controls the first and second backlight units so that adriving electric power is applied to the first backlight unit in a mainmode and a driving electric power is applied to the second backlightunit in the main driving mode and a sub mode.

Another exemplary embodiment of a display device includes a backlightassembly and a display panel. The backlight assembly includes a firstlight source, a second light source and a light guiding unit. The firstlight source generates a first light. The second light source generatesa second light having a different color from the first light. The lightguiding unit guides the first and second lights. The display panelincludes a main display part and a sub display part. The main displaypart changes a color of the first light to display main images. The subdisplay part displays sub images using the second light. A color of thesecond light is substantially unchanged.

An exemplary embodiment of display substrate includes a base substrate,a plurality of switching elements and a reflecting plate. The basesubstrate has a sub driving region and a main driving region. Theswitching elements are in pixel regions that are in the sub drivingregion and the main driving region, respectively. The reflecting plateis electrically connected to each of the switching elements in the subdriving region to reflect an externally provided light.

An exemplary embodiment of a method of manufacturing a display isprovided as follows. A switching element having a drain electrodeoutputting a data signal is formed on a base substrate having a subdriving region and a main driving region. A protective insulating layeris formed on an insulating layer that covers the switching element. Theprotective insulating layer has a contact hole through which the drainelectrode is partially exposed. A transparent electrode is formed on theprotective insulating layer. The transparent electrode is electricallyconnected to the drain electrode exposed through the contact hole. Areflecting plate is formed on the transparent electrode in the subdriving region. The reflecting plate divides a pixel region in the subdriving region into a reflection portion and a transmission portion.

Another exemplary embodiment of a display device includes a displaysubstrate, an opposite substrate and a liquid crystal layer. The displaysubstrate includes a first substrate, a switching element and areflecting plate. The first substrate has a sub driving region and amain driving region. The switching element is in each of pixel regionsin the sub driving region and the main driving region. The reflectingplate is in the pixel regions in the sub driving region to beelectrically connected to the switching element. An externally providedlight is reflected from the reflecting plate. The opposite substratecorresponds to the display substrate. The liquid crystal layer isinterposed between the display substrate and the opposite substrate.

In exemplary embodiments, the backlight assembly can be used for variousdisplay devices such as a liquid crystal display (LCD) device, anelectrophoresis display device, etc. The display device includes the LCDdevice, an organic light emitting display (OLED) device, theelectrophoresis display device, etc.

In exemplary embodiments of the backlight assembly and the displaydevice, the different lights are incident into the main and sub displayparts, so that the main and sub display parts may be independentlyoperated. Therefore, a power consumption of the backlight assembly andthe display device is decreased, and a luminance of the sub display partis increased.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other advantages of the present invention will become moreapparent by describing in detail example embodiments thereof withreference to the accompanying drawings, in which:

FIG. 1 is a perspective view illustrating an exemplary embodiment of abacklight assembly in accordance with the present invention;

FIG. 2 is an exploded perspective view illustrating the backlightassembly shown in FIG. 1;

FIG. 3 is a cross-sectional view taken along line I-I′ shown in FIG. 2;

FIGS. 4A and 4B are timing diagrams illustrating an exemplary embodimentof an operation of the backlight assembly shown in FIG. 1;

FIG. 5 is a perspective view illustrating another exemplary embodimentof a backlight assembly in accordance with another embodiment of thepresent invention;

FIG. 6 is a perspective view illustrating another exemplary embodimentof a backlight assembly in accordance with another embodiment of thepresent invention;

FIG. 7 is a perspective view illustrating another exemplary embodimentof a backlight assembly in accordance with another embodiment of thepresent invention;

FIG. 8A is a timing diagram illustrating an exemplary embodiment of adriving signal applied to first and second light sources shown in FIG. 7in a main driving mode;

FIG. 8B is a graph illustrating an exemplary embodiment of a luminancealong a cross-section taken along line II-II′ shown in FIG. 7 in a maindriving mode;

FIG. 9A is a timing diagram illustrating an exemplary embodiment of adriving signal applied to first and second light sources shown in FIG. 7in a sub driving mode;

FIG. 9B a graph illustrating an exemplary embodiment of a luminancealong a cross-section taken along line II-II′ shown in FIG. 7 in a subdriving mode;

FIG. 10 is an exploded perspective view illustrating a backlightassembly in accordance with another embodiment of the present invention;

FIGS. 11A and 11B are timing diagrams illustrating driving signalsapplied to first and second light-emitting diodes shown in FIG. 10;

FIG. 12 is a cross-sectional view taken along a line III-III′ shown inFIG. 10;

FIG. 13 is a cross-sectional view illustrating another exemplaryembodiment of a backlight assembly in accordance with the presentinvention;

FIG. 14 is a perspective view illustrating an exemplary embodiment of adisplay device in accordance with the present invention;

FIG. 15 is an exploded perspective view illustrating the display deviceshown in FIG. 14;

FIG. 16 is a cross-sectional view taken along line IV-IV′ shown in FIG.15;

FIG. 17 is an exploded perspective view illustrating another exemplaryembodiment of a display device in accordance with the present invention;

FIG. 18 is a cross-sectional view illustrating a display panel takenalong line V-V′ shown in FIG. 17;

FIG. 19A is a cross-sectional view illustrating the display panel takenalong line V-V′ shown in FIG. 17 in a main driving mode;

FIG. 19B is a cross-sectional view illustrating the display panel takenalong line V-V′ shown in FIG. 17 in a sub driving mode;

FIG. 20 is an exploded perspective view illustrating another exemplaryembodiment of a display device in accordance with the present invention;

FIG. 21 is a plan view illustrating an exemplary embodiment of a displaysubstrate in accordance with the present invention;

FIG. 22 is an enlarged plan view illustrating portion ‘A’ shown in FIG.21;

FIG. 23 is a cross-sectional view taken along line VI-VI′ shown in FIG.22;

FIG. 24 is an enlarged plan view illustrating portion ‘B’ shown in FIG.21;

FIG. 25 is a cross-sectional view taken along line VII-VII′ shown inFIG. 24;

FIG. 26 is a plan view illustrating another exemplary embodiment of adisplay substrate in accordance with the present invention;

FIGS. 27 to 29 are cross-sectional views illustrating an exemplaryembodiment of a method of manufacturing an array substrate in accordancewith the present invention; and

FIG. 30 is a cross-sectional view illustrating another exemplaryembodiment of a display device in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention is described more fully hereinafter with reference to theaccompanying drawings, in which embodiments of the invention are shown.This invention may, however, be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein.Rather, these embodiments are provided so that this disclosure will bethorough and complete, and will fully convey the scope of the inventionto those skilled in the art. In the drawings, the size and relativesizes of layers and regions may be exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on” or “connected to” another element or layer, it can bedirectly on or connected to the other element or layer or interveningelements or layers may be present. In contrast, when an element isreferred to as being “directly on” or “directly coupled to” anotherelement or layer, there are no intervening elements or layers present.Like numbers refer to like elements throughout. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present invention.

Spatially relative terms, such as “lower,” “upper” and the like, may beused herein for ease of description to describe one element or feature'srelationship to another element(s) or feature(s) as illustrated in thefigures. It will be understood that the spatially relative terms areintended to encompass different orientations of the device in use oroperation in addition to the orientation depicted in the figures. Forexample, if the device in the figures is turned over, elements describedas “lower” relative to other elements or features would then be orientedas “upper” relative to the other elements or features. Thus, theexemplary term “lower” can encompass both an orientation of above andbelow. The device may be otherwise oriented (rotated 90 degrees or atother orientations) and the spatially relative descriptors used hereininterpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Embodiments of the invention are described herein with reference tocross-section illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of the invention. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments of the invention should not be construed aslimited to the particular shapes of regions illustrated herein but areto include deviations in shapes that result, for example, frommanufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the figures are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to limit the scope ofthe invention.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, the present invention will be described in detail withreference to the accompanying drawings.

FIG. 1 is a perspective view illustrating an exemplary embodiment of abacklight assembly in accordance with the present invention. FIG. 2 isan exploded perspective view illustrating the backlight assembly shownin FIG. 1.

Referring to FIGS. 1 and 2, the backlight assembly 100 includes a firstbacklight unit 130, a second backlight unit 150 and a light blockingmember 112.

The backlight assembly 100 supplies a light to a display panel includinga main display part and a sub display part. Main images are selectivelydisplayed on the main display part. Sub images are constantly displayedon the sub display part. The first and second backlight units 130 and150 generate the light in a main driving mode. In a sub driving mode,the first backlight unit 130 does not generate the light and the secondbacklight unit 150 generates the light.

The first backlight unit 130 generates a first light in the main drivingmode and does not generate the first light in the sub driving mode.

The first backlight unit 130 includes a first light source 131 and afirst light guiding unit 133.

The first light source 131 supplies the first light guiding unit 133with the first light. In FIG. 2, the first light source 131 includes alight-emitting diode (LED). Alternative exemplary embodiments mayinclude the first light source 131 as a lamp.

The first light guiding unit 133 guides the first light toward the maindisplay part to increase a luminance uniformity of the first light. Thefirst light guiding unit 133 may include a light guiding material havingvarious characteristics such as high light transmittance, high heatresistance, high chemical resistance, high mechanical strength, etc.Exemplary embodiments of a material that can be used for the first lightguiding unit 133 include, but are not limited to, polymethylmethacrylate(PMMA), polyamide, polyimide, polypropylene, polyurethane and anycombination including at least one of the foregoing. In FIG. 2, thefirst light guiding unit 133 has a substantially flat shape. Alternativeexemplary embodiments may include configurations where the first lightguiding unit 133 may have a wedge shape. That is, a thickness of thefirst light guiding unit 133 may be decreased as a distance from a lightincident surface of the first light guiding unit 133 is increased.

The first backlight unit 130 may further include first optical sheets138.

The first optical sheets 138 improve optical characteristics of thefirst light exiting the first light guiding unit 133. The first opticalsheets 138 may include a first reflecting sheet 135, a first diffusionsheet 136 and/or a first brightness enhancement sheet 137.

The first reflecting sheet 135 is under the first light guiding unit133. A portion of the light leaked from the first light guiding unit 133is reflected from the first reflecting sheet 135 toward the first lightguiding unit 133.

The first diffusion sheet 136 is disposed on the first light guidingunit 133 to diffuse the first light exiting the first light guiding unit133, thereby increasing luminance uniformity.

The first brightness enhancement sheet 137 is disposed on the firstdiffusion sheet 136 to increase a luminance when the displace deviceincluding the backlight assembly is viewed on a plane. In FIG. 2, thefirst light guiding unit 133 includes two first brightness enhancementsheets 137 and longitudinal directions of the first brightnessenhancement sheets 137 are substantially in parallel to each other. Inalternative exemplary embodiments, there may be any of a number of firstoptical sheets 138 and/or first brightness enhancement sheets 137 as issuitable for the purposes described herein.

The second backlight unit 150 generates a second light in the maindriving mode and the sub driving mode. The second backlight unit 150includes a second light source 151 and a second light guiding unit 153.

The second light source 151 supplies the second light guiding unit 153with the second light. In FIG. 2, the second light source 151 includes alight-emitting diode. Alternative exemplary embodiments may include thesecond light source 151 as a lamp.

The second light guiding unit 153 guides the second light havingincreased luminance uniformity toward the sub display part.

The second backlight unit 150 may further include second optical sheets158. The second optical sheets 158 improve optical characteristics suchas luminance uniformity, a luminance when viewed on a plane, etc., ofthe second light exiting the second light guiding unit 153. The secondoptical sheets 158 may include a second reflecting sheet 155, a seconddiffusion sheet 156 and/or a second brightness enhancement sheet 157.The second reflecting sheet 155, the second diffusion sheet 156 and thesecond brightness enhancement sheet 157 of the second backlight unit 150are substantially the same as the first reflecting sheet 135, the firstdiffusion sheet 136 and the first brightness enhancement sheet 137 ofthe first backlight unit 130. Thus, any further explanation concerningthe above elements for the second backlight unit 150 will be omitted.

The backlight assembly 100 may further include a receiving container 110to receive the first and second backlight units 130 and 150. Thereceiving container 110 includes a bottom plate 111, a first sidewall113, a second sidewall 115, a third sidewall 117 and a fourth sidewall119.

The first, second, third and fourth sidewalls 113, 115, 117 and 119 areprotruded from edges or sides of the bottom plate 111. Alternativeexemplary embodiments include configurations where the bottom plate 111may have an opening to decrease an overall weight and size of thebacklight assembly 100. The first sidewall 113 faces (and are consideredopposite to) the second sidewall 115. The third sidewall 117 faces thefourth sidewall 119. Each of the third and fourth sidewalls 117 and 119is connected to the first and second sidewalls 113 and 115,respectively.

A first recess (not shown) is formed on the first sidewall 113, and ahole (not shown) is formed through a peripheral portion of the bottomplate 111 corresponding to the first recess (not shown). A second recess116 is formed on the second sidewall 115, and a hole is formed through aperipheral portion of the bottom plate 111 corresponding to the secondrecess 116. In exemplary embodiments, first and second guiding groovesmay be formed on an outer surface of the first sidewall 113.

The light blocking member 112 is interposed between the first backlightunit 130 and the second backlight unit 150 to optically isolate thefirst backlight unit 130 from the second backlight unit 150. That is,the light blocking member 112 prevents a leakage of the first light fromthe first backlight unit 130 to the second backlight unit 150 and aleakage of the second light from the second backlight unit 150 to thefirst backlight unit 130. The light blocking member 112 may be ablocking wall protruded from the bottom plate 111 as illustrated in FIG.2. Alternative exemplary embodiments may include configurations wherethe light blocking member 112 may be a light blocking sheet between thefirst and second light guiding units 133 and 153.

The light blocking member 112 divides a receiving space of the receivingcontainer 110 into a main receiving region and a sub receiving region.The bottom plate 111, the light blocking member 112 and the first, thirdand fourth sidewalls 113, 117 and 119 define the main receiving region.The bottom plate 111, the light blocking member 112 and the second,third and fourth sidewalls 115, 117 and 119 define the sub receivingregion. The bottom plate 111 corresponding to the main receiving regionhas a first area. The bottom plate 111 corresponding to the subreceiving region has a second area that is smaller than the first area.

FIG. 3 is a cross-sectional view taken along line I-I′ shown in FIG. 2.

Referring to FIGS. 2 and 3, the first reflecting sheet 135, the firstlight guiding unit 133, the first diffusion sheet 136 and the firstbrightness enhancement sheet 137 are received in the main receivingregion, in sequence. The second reflecting sheet 155, the second lightguiding unit 153, the second diffusion sheet 156 and the secondbrightness enhancement sheet 157 are received in the sub receivingregion, in sequence.

The backlight assembly 100 may further include a power supplying part105 (FIGS. 1 and 2) and a power printed circuit film 170, such as anelectric power supplying part and an electric power printed circuitfilm.

The electric power supplying part 105 may be electrically connected tothe first and second light sources 131 and 151 through the electricpower printed circuit film 170. The electric power printed circuit film170 is extended from the first sidewall 113 of the receiving container110 toward the second sidewall 115. The first light source 131 ismounted on a first end portion of the electric power printed circuitfilm 170 adjacent to the first sidewall 113. The second light source 151is mounted on a second end portion of the electric power printed circuitfilm 170, and the second end portion is opposite to the first endportion of the electric power printed circuit film 170. The first lightsource 131 is received in the first recess (not shown) of the firstsidewall 113 through the hole (not shown) of the bottom plate 111corresponding to the first recess (not shown). The second light source151 is received in the second recess 116 of the second sidewall 115through the hole of the bottom plate 111 corresponding to the secondrecess 116. The electric power printed circuit film 170 may furtherinclude an electric power transmitting line 171 that is extended fromthe electric power printed circuit film 170. The electric power printedcircuit film 170 may be electrically connected to the electric powersupplying part 105 through the electric power transmitting line 171.

FIGS. 4A and 4B are timing diagrams illustrating an exemplary embodimentof an operation of the backlight assembly shown in FIG. 1.

Referring to FIGS. 2 to 4B, in the main mode, the electric powersupplying part 105 applies an electric power for driving the first lightsource DM1 (131 shown in FIG. 2) and the second light source DS1 (151shown in FIG. 2). In the sub mode, the electric power supplying part 105applies the electric power to the second light source DS1, so that thesecond light source DS1 generates the second light, and the first lightsource DM1 does not generate the first light. Therefore, a powerconsumption of the sub mode is decreased and an amount of the secondlight incident into the sub display part is increased in the sub mode.

FIG. 5 is a perspective view illustrating another exemplary embodimentof a backlight assembly in accordance with the present invention. In anexemplary embodiment as illustrated in FIG. 5, the backlight assemblymay be substantially frame shaped. For orientation purposes, a Cartesiancoordinate system may be used where a first side of the display deviceextends along a Y-axis direction, and a second side of the displaydevice extends along an X-axis direction, where the Y-axis issubstantially perpendicular to the X-axis.

Referring to FIG. 5, the backlight assembly 240 includes a light sourceunit 211 and a light guiding unit 230. The backlight assembly 240supplies a light to a display panel including a main display part and asub display part. Main images and sub images are selectively displayedon the main display part and the sub display part, respectively. Thatis, the backlight assembly 240 is driven in the main mode for drivingthe main display part of the display panel to form a main screen, and isdriven in the sub mode for driving the sub display part of the displaypanel to form a sub screen using a smaller power consumption than themain mode.

The light source unit 211 may generate lights of various colors based ondriving modes. In exemplary embodiments, the light source unit 211 mayinclude a first light source (not shown) and a second light source (notshown). The first light source (not shown) generates a first light tosupply the main display part with the first light in the main mode. Thesecond light source (not shown) generates a second light to supply thesub display part with the second light in the sub mode. The second lightmay have a different color from the first light. In one exemplaryembodiment, the first light is a white light and the second light is acolored light. The colored light may include one of red, green and bluelights.

The light guiding unit 230 guides the first light or the second lighttoward the display panel. In FIG. 5, the light guiding unit 230 includesa light incident surface 231 and a light exiting surface 235.

The light incident surface 231 faces the light source unit 211. Thefirst light or the second light that is incident into the light guidingunit 230 through the light incident surface 231 is repetitivelyreflected and refracted in the light guiding unit 230 to exit the lightexiting surface 235.

The light guiding unit 230 guides the first and second lights anddiffuses the first and second lights to an end portion of the lightguiding unit 230 facing the light incident surface 231, so that thefirst and second lights exiting the light exiting surface 235 have aplanar shape. That is, the first and second lights may exit an entire ofthe light exiting surface 235.

FIG. 6 is a perspective view illustrating another exemplary embodimentof a backlight assembly in accordance with the present invention.

Referring to FIG. 6, the backlight assembly 280 includes a light sourceunit 250 and a light guiding unit 270.

The light source unit 250 includes a first light source and a secondlight source.

The first light source generates a first light that may be a whitelight. The second light source generates a second light that may be acolored light such as being one of red, green and blue lights. The colorof the first light generated from the first light source and the colorof the second light generated from the second light source may bechanged or reversed. In FIG. 6, each of the first and second lightsources may include a light-emitting diode. The light-emitting diodedirectly converts an electric power into the light so that thelight-emitting diode has various characteristics such as a longlifetime, a low power consumption, etc.

In FIG. 6, the first light source includes two first light-emittingdiodes 251 and 253 that generate the white light. The second lightsource includes a second light-emitting diode 255 that generates one ofthe red, green and blue lights. The number of the light-emitting diodesand the location of the light-emitting diodes with respect to the lightguiding unit 270 may be changed based on a size and a luminance of thebacklight assembly 280. Alternative exemplary embodiments may includeconfigurations where each of the first and second light sources mayinclude a lamp.

The backlight assembly 280 may further include an electric powersupplying part 220 that applies an electric power to the first andsecond light sources.

The electric power supplying part 220 is electrically connected to thefirst and second light-emitting diodes 251, 253 and 255. In the mainmode, the electric power supplying part 220 applies the electric powerto the first light-emitting diodes 251 and 253. In the sub mode, theelectric power supplying part 220 applies the electric power to thesecond light emitting diode 255.

In the main mode, the first light of the white color exits the lightguiding unit 270. In the sub mode, the second light of one of the red,green and blue colors exits the light guiding unit 270.

In FIG. 6, the light guiding unit 270 has a substantially flat shapeincluding a light incident surface 271 and a light exiting surface 275.Alternative exemplary embodiments include configurations where the lightguiding unit 270 may have a wedge shape. That is, a thickness of thelight guiding unit 270 may be decreased, as a distance from the lightincident surface 271 of the light guiding unit 270 is increased. Thelight incident surface 271 forms a side surface of the light guidingunit 270, and the light exiting surface 275 is connected to the lightincident surface 271 forming a predetermined angle with respect to thelight incident surface 271.

In FIG. 6, two first light-emitting diodes 251 and 253 are on the lightincident surface 271 of the light guiding unit 270, and one secondlight-emitting diode 255 is on the light incident surface 271 betweenthe first light-emitting diodes 251 and 253. That is, the firstlight-emitting diodes 251 and 253 and the second light-emitting diode255 are arranged substantially in parallel with the light incidentsurface 271 of the light guiding unit 270. The first light or the secondlight is incident into the light guiding unit 270 through the lightincident surface 271 based on the mode of the backlight assembly 280.The guided first light or the second light exits the light exitingsurface 275.

The light guiding unit 270 may include a light guiding material havingvarious characteristics such as high light transmittance, high heatresistance, high chemical resistance, high mechanical strength, etc.Examples of a material that can be used for the light guiding unit 270include polymethylmethacrylate (PMMA), polyamide, polyimide,polypropylene, polyurethane, etc.

FIG. 7 is a perspective view illustrating another exemplary embodimentof a backlight assembly in accordance with the present invention.

Referring to FIG. 7, the backlight assembly 300 includes a light sourceunit 310, an electric power supplying part 320 and a light guiding unit350. The backlight assembly of FIG. 7 is the same as in FIG. 2 exceptfor a location of a light source unit. Thus, any further explanationconcerning the above elements will be omitted.

The light source unit 310 includes first light-emitting diodes 311 and313 and a second light-emitting diode 315. In one exemplary embodiment,the first light-emitting diodes 311 and 313 generate a first light thatmay be a white light and the second light-emitting diodes 315 generatesa second light that may one of red, green and blue lights.

The light guiding unit 350 includes a substantially plate shape having afirst side surface 351, a second side surface 353 and a light exitingsurface 355. The first side surface 351 is substantially in parallelwith a first (traverse) direction (y-direction) of the light guidingunit 350. The second side surface 353 is substantially in parallel witha second (longitudinal) direction (x-direction) that is substantially inperpendicular to the first direction.

The light exiting surface 355 is connected between the first and secondside surfaces 351 and 353. The light exiting surface 355 includes a mainregion MS and a sub region SS that is substantially parallel with themain region MS in the first direction. The first light-emitting diodes311 and 313 are disposed on the first surface 351 and the secondlight-emitting diode 315 is disposed on the second side surface 353.

Alternative exemplary embodiments include configurations where thesecond light-emitting diode 315 may be on a third surface of the lightguiding unit 350 facing the first side surface 351 or on a fourthsurface opposite to the second surface 353 in FIG. 7.

FIG. 8A is a timing diagram illustrating an exemplary embodiment of adriving signal applied to first and second light sources shown in FIG. 7in a main mode. FIG. 8B is a graph illustrating an exemplary embodimentof a luminance along a cross-section taken along line II-II′ shown inFIG. 7 in a main mode.

Referring to FIGS. 7, 8A and 8B, in the main mode, the electric powersupplying part 320 applies an electric power to the first light-emittingdiodes DM1 and DM2 (311 and 313 shown in FIG. 7), and does not apply theelectric power to the second light-emitting diode DS1 (315 shown in FIG.7). Therefore, the white light generated from the first light-emittingdiodes DM1 and DM2 (311 and 313 shown in FIG. 7) is incident into thelight guiding unit 350 through the first side surface 351.

The first light is the white light that may not be refracted on thefirst side surface 351. The first light is incident into the first sidesurface 351 at a predetermined incident angle. The first light that isincident into the light guiding unit 350 through the first surface 351is repetitively reflected and refracted in the light guiding unit 350 toexit the light exiting surface 355. An incident angle of the first lightwith respect to the light exiting surface 355 is decreased, as thenumber of the reflection and refraction is increased. Therefore, theguided first light exits the light exiting surface 355 at a uniformluminance.

Referring again to FIGS. 7 and 8B, the first light exits the main andsub regions MS and SS of the light exiting surface 355. A luminancedifference between the main and sub regions MS and SS is negligible, sothat the guided first light exits the light exiting surface 355 at theuniform luminance.

FIG. 9A is a timing diagram illustrating an exemplary embodiment of adriving signal applied to first and second light sources shown in FIG. 7in a sub mode. FIG. 9B a graph illustrating an exemplary embodiment of aluminance along a cross-section taken along line II-II′ shown in FIG. 7in a sub mode.

Referring to FIGS. 7, 9A and 9B, in the sub mode, the electric powersupplying part 320 applies the electric power to the secondlight-emitting diode DS1 (315 shown in FIG. 7), and does not apply theelectric power to the first light-emitting diodes DM1 and DM2 (311 and313 shown in FIG. 7). Therefore, one of the red, green and blue lightsgenerated from the second light-emitting diode DS1 (315 shown in FIG. 7)is incident into the light guiding unit 350 through the second sidesurface 353.

The second light is one of the red, green and blue lights that may berefracted toward the second direction (x-direction) on the second sidesurface 353. The second light that is incident into the light guidingunit 350 through the second surface 353 is repetitively reflected andrefracted in the light guiding unit 350 to exit the light exitingsurface 355. An incident angle of the second light with respect to thelight exiting surface 355 is decreased, as the number of the reflectionand refraction is increased. In FIG. 9B, the guided second light isconcentrated on the sub region SS.

FIG. 10 is an exploded perspective view illustrating an exemplaryembodiment of a backlight assembly in accordance with the presentinvention.

Referring to FIG. 10, the backlight 400 includes a light source unit 410and a light guiding unit 430. The light source unit 410 of the backlightassembly of FIG. 10 is the same as the light source unit 310 in FIG. 7except for the number of first light-emitting diodes and an electricpower printed circuit film 419. Thus, any further explanation concerningthe above elements will be omitted.

The light source unit 410 includes a first light source and a secondlight source. The first light source generates a first light and thesecond light source generates a second light. In exemplary embodiments,the second light may have a different color from the first light. InFIG. 10, the first light source includes a plurality of firstlight-emitting diodes 411 and the second light source includes a secondlight-emitting diode 417.

The light source unit 410 may further include the electric power printedcircuit film 419. The electric power printed circuit film 419 may have asubstantially T-shape. The electric power printed circuit film 419 mayfurther include an electric power transmitting line that is electricallyconnected to the first and second light-emitting diodes 411 and 417. Theelectric power printed circuit film 419 may be electrically connected tothe electric power supplying part 420. Three of the first light-emittingdiodes 411 are on an upper portion of the T-shaped electric powerprinted circuit film 419. The second light-emitting diode 417 is on alower portion of the T-shaped electric power printed circuit film 419.

The backlight assembly 400 may further include the electric powersupplying part 420. The electric power supplying part 420 iselectrically connected to the electric power printed circuit film 419.The electric power supplying part 420, unlike the electric powersupplying part 320 in FIG. 7, applies an electric power to the first andsecond light-emitting diodes 411 and 417 in the main mode and appliesthe electric power to the second light-emitting diode 417 in the submode.

FIGS. 11A and 11B are timing diagrams illustrating driving signalsapplied to first and second light-emitting diodes shown in FIG. 10.

Referring to FIGS. 11A and 11B, the first light-emitting diodes DM1 andDM2 (411 shown in FIG. 10) generates a first light that may be the whitelight in the main mode and does not generate the first light in the submode. The second light-emitting diode DS1 (417 shown in FIG. 10)generates a second light that may be one of the red, green and bluelights in the main mode and the sub mode. That is, the secondlight-emitting diode DS1 (417 shown in FIG. 10) of the backlightassembly 400, unlike the backlight assemblies 240, 280, and 300constantly generates the second light in the main mode as well as in thesub mode.

FIG. 12 is a cross-sectional view taken along line III-III′ shown inFIG. 10.

Referring to FIGS. 10 and 12, the backlight assembly 400 may furtherinclude a receiving container 470. The receiving container 470 includesa bottom plate 471, a first sidewall 473, a second sidewall 475, a thirdsidewall 477 and a fourth sidewall 479.

Alternative exemplary embodiments may include configurations where thebottom plate 471 may have an opening to decrease weight and size of thebacklight assembly 400. The first, second, third and fourth sidewalls473, 475, 477 and 479 are protruded from sides of the bottom plate 471.The first sidewall 473 faces the second sidewall 475. The third sidewall477 faces the fourth sidewall 479. Each of the third and fourthsidewalls 477 and 479 is connected to the first and second sidewalls 473and 475, respectively.

Three of first recesses (not shown) are formed on the first sidewall473, and three holes (not shown) are formed through a peripheral portionof the bottom plate 471 corresponding to the first recesses (not shown).A second recess 476 is formed on the second sidewall 475 and a hole isformed through a peripheral portion of the bottom plate 471corresponding to the second recess 476.

The first light sources 411 are received in the first recesses (notshown) of the first sidewall 473 through the holes (not shown) of thebottom plate 471 corresponding to the first recesses (not shown),respectively. The second light source 417 is received in the secondrecess 476 of the second sidewall 475 through the hole of the bottomplate 471 corresponding to the second recess 476. A first guiding grooveand a second guiding groove may be formed on an outer surface of thefirst sidewall 473. An upper portion of the T-shaped electric powerprinted circuit film 419 is bent and surrounds the second guidinggroove. The electric power printed circuit film 419 is electricallyconnected to the electric power supplying part 420.

The receiving container 470 may further include a partition wall 472.The partition wall 472 is interposed between the first and secondsidewalls 473 and 475 and is connected to the third and fourth sidewalls477 and 479.

The partition wall 472 divides a receiving space of the receivingcontainer 470 into a main receiving region and a sub receiving region.The bottom plate 471, the partition wall 472 and the first, third andfourth sidewalls 473, 477 and 479 define the main receiving region. Thebottom plate 471, the partition wall 472 and the second, third andfourth sidewalls 475, 477 and 479 define the sub receiving region. Thebottom plate 471 corresponding to the main receiving region has a firstarea. The bottom plate 471 corresponding to the sub receiving region hasa second area that is smaller than the first area.

The light guiding unit 430 includes a main light guiding plate 431 a sublight guiding plate 435 and optical sheets.

The main and sub light guiding plates 431 and 435 have a substantiallythe same material as the light guiding unit shown in FIGS. 5 to 7, andthus any further explanation concerning the above elements will beomitted.

The main light guiding plate 431 is received in a main receiving regionof the receiving container 470 and the sub light guiding plate 435 isreceived in a sub receiving region of the receiving container 470. Themain light guiding plate 431 is substantially in parallel with the sublight guiding plate 435.

The main light guiding plate 431 guides the first light that is incidentinto the main light guiding plate 431 through a side surface facing thefirst sidewall 473 toward an upper portion of the backlight assembly400. The sub light guiding plate 435 guides the second light that isincident into the sub light guiding plate 435 through a side surfacefacing the second sidewall 475 toward the upper portion of the backlightassembly 400

The partition wall 472 is interposed between the main light guidingplate 431 and the sub light guiding plate 435, so that the main lightguiding plate 431 is optically isolated from the sub light guiding plate435. In exemplary embodiments, a highly reflective layer may be formedon the partition wall 472 to promote an efficiency of light use. In oneexemplary embodiment, an aluminum layer is formed on the partition wall472.

The optical sheets include main optical sheets 441 and sub opticalsheets 451.

The main optical sheets 441 improve optical characteristics of the firstlight exiting the main light guiding plate 431. The main optical sheets441 include a main reflecting sheet 443, a main diffusion sheet 445 anda main brightness enhancement sheet 447.

The main reflecting sheet 443 is interposed between the bottom plate 471and the main light guiding plate 431. A portion of the first lightleaked from the main light guiding plate 431 is reflected from the mainreflecting sheet 443 toward the main light guiding plate 431. The maindiffusion sheet 445 is on the main light guiding plate 431 to diffusethe first light, thereby increasing a luminance uniformity of the firstlight.

The main brightness enhancement sheet 447 is on the main diffusion sheet445 to increase a luminance of the first light when viewed on a plane.In FIG. 10, the main brightness enhancement sheet 447 includes twobrightness enhancement sheets having different longitudinal directionsthat are substantially in perpendicular to each other.

The sub optical sheets 451 improve optical characteristics of the secondlight exiting the sub light guiding plate 451. The sub optical sheets451 include a sub reflecting sheet 453, a sub diffusion sheet 455 and asub brightness enhancement sheet 457. The sub optical sheets 451 aresubstantially the same as the main optical sheets 441 except for a size,and thus any further explanation concerning the above elements will beomitted. Alternative exemplary embodiments may include the sub opticalsheets 451 including a dual brightness enhancement film (DBEF).

FIG. 13 is a cross-sectional view illustrating another exemplaryembodiment of a backlight assembly in accordance with the presentinvention.

Referring to FIG. 13, the backlight assembly 500 includes a light sourceunit, an electric power supplying part, a light guiding unit and areceiving container. The backlight assembly of FIG. 13 is the same as inFIGS. 10 to 12 except for a light guiding unit and a receivingcontainer. Thus, the same reference numerals will be used to refer tothe same or like parts as those described in FIGS. 10 to 12 and anyfurther explanation concerning the above elements will be omitted.

The light guiding unit of FIG. 13 is the same as in FIGS. 10 to 12except for optical sheets and a reflecting layer. In FIGS. 10 to 12, thelight guiding unit is divided into the main light guiding sheets and thesub light guiding sheets. However, in FIG. 13, the light guiding unitincludes the optical sheets for covering main and sub light guidingplates and the reflecting layer. Thus, any further explanationconcerning the above elements will be omitted.

The optical sheets improve optical characteristics of a first lightexiting a main light guiding plate 531 and a second light exiting a sublight guiding plate 535. The optical sheets include a reflecting sheet543, a diffusion sheet 545 and a brightness enhancement sheet 547.

The reflecting sheet 543 is interposed among the bottom plate 571 andthe main and sub light guiding plates 531 and 535. A portion of thefirst light leaked from the main light guiding plate 531 and a portionof the second light leaked from the sub light guiding plate 535 arereflected from the reflecting sheet 543 toward the main and sub lightguiding plates 531 and 535.

A reflecting layer 537 is interposed between the main and sub lightguiding plates 531 and 535. The reflecting layer 537 includes a highlyreflective material such as an aluminum. The reflecting layer 537 may becoated on a surface of the main light guiding plate 531 or the sub lightguiding plate 535. In alternative exemplary embodiments, the reflectinglayer 537 may be attached to the surface of the main light guiding plate531 or the sub light guiding plate 535.

The diffusion sheet 545 is on the main and sub light guiding plates 531and 535 to diffuse the first light exiting the main light guiding plate531 and the second light exiting the sub light guiding plate 535,thereby increasing a luminance uniformity of the first and secondlights.

The brightness enhancement sheet 547 is on the diffusion sheet 545 toincrease a luminance of the first and second lights when viewed on aplane. In FIG. 13, the brightness enhancement sheet 547 includes twobrightness enhancement sheets having different longitudinal directionsthat are substantially in perpendicular to each other. The receivingcontainer of FIG. 13 is substantially the same as in FIGS. 10 to 12except the partition wall. In FIG. 13, the partition wall is omitted.Thus, any further explanation concerning the above elements will beomitted.

FIG. 14 is a perspective view illustrating an exemplary embodiment of adisplay device in accordance with the present invention. FIG. 15 is anexploded perspective view illustrating the display device shown in FIG.14.

Referring to FIGS. 14 and 15, the display device 600 includes a displaypanel 690, a backlight assembly and a driving circuit member 620. Thebacklight assembly includes a first backlight assembly unit 630 and asecond backlight assembly unit 650. The first and second backlightassembly units of FIGS. 14 and 15 are substantially the same as in FIGS.1 to 3, and thus any further explanation concerning the above elementswill be omitted.

The display device 600 may further include an electric power printedcircuit film 670 and a receiving container 610. The electric powerprinted circuit film and the receiving container of FIGS. 14 and 15 aresubstantially the same as in FIGS. 1 to 3, and thus any furtherexplanation concerning the above elements will be omitted.

FIG. 16 is a cross-sectional view taken along line IV-IV′ shown in FIG.15.

Referring to FIGS. 14 to 16, the display panel 690 displays images usinga first light generated from the first backlight assembly unit 630 and asecond light generated from the second backlight assembly unit 650. Thedisplay panel 690 includes a main display part MDP and a sub displaypart SDP. In a main mode, a main image is displayed on the main displaypart MDP and a sub image is displayed on the sub display part SDP. In asub mode, the main image is not displayed on the main display part MDPand the sub image is displayed on the sub display part SDP.

The main display part MDP displays main images based on the first lightgenerated from the first backlight unit 630 in the main mode. The mainimages may include a moving image, a character, etc. The main images arenot displayed on the main display part MDP in the sub mode.

The sub display part SDP displays the sub images based on the secondlight generated from the second backlight unit 650 in the main mode andthe sub mode. The sub images may include a time, a data, a batterystate, etc.

The display panel 690 includes a first substrate 691, a second substrate695 and a liquid crystal layer 696. The display panel 690 may driven ina dual mode having the main mode and the sub mode.

The first substrate 691 is on stepped portions of first, second, thirdand fourth sidewalls 613, 615, 617 and 619 of the receiving container610. The first substrate 691 may include a lower substrate (not shown)and a plurality of thin film transistors (TFTs) (not shown). The lowersubstrate may include a transparent insulating material. The thin filmtransistors are arranged on the lower substrate in a substantiallymatrix shape. The thin film transistors correspond to pixel electrodesof the first substrate 691. Each of the pixel electrodes may include atransparent conductive material. Each of the thin film transistorsapplies a panel driving signal to each of the pixel electrodes.

In order to drive the first substrate 691 in the main and sub modes, thefirst substrate 691 includes a main pixel part (not shown) and a subpixel part (not shown). In the main mode, a first driving signal isapplied to a portion of the pixel electrodes on the main pixel part todisplay a main image. In the main mode and the sub mode, a seconddriving signal is applied to a portion of the pixel electrodes on thesub pixel part to display a sub image.

The second substrate 695 is spaced apart from the first substrate 691 bya substantially constant distance. The second substrate 695 may includean upper substrate and red, green and blue color filters. The red, greenand blue color filters correspond to the pixel electrodes, respectively.The red, green and blue color filters are arranged on the uppersubstrate in a substantially matrix shape. Each of the red, green andblue color filters transmits a color light to display color images. Acommon electrode may be formed on an entire of the second substrate 695facing the first substrate 691. The common electrode may include atransparent conductive material.

The second substrate 695 includes a main color filter part (not shown)and a sub color filter part (not shown). The main color filter part ofthe second substrate 695 corresponds to the main pixel part of the firstsubstrate 691. The main color filter part and the main pixel part formthe main display part MDP. The sub color filter part of the secondsubstrate 695 corresponds to the sub pixel part of the first substrate691. The sub color filter part and the sub pixel part form the subdisplay part SDP. The red, green and blue color filters of the maincolor filter part may have a different size from the red, green and bluecolor filters of the sub color filter part, so that the main displaypart MDP may have a different resolution from the sub display part SDP.

The second substrate 695 may further include a black matrix. The blackmatrix is between the red, green and blue color filters to defineregions of the red, green and blue color filters and a boundary betweenthe main and sub display parts MDP and SDP.

The display panel 690 may further include a panel printed circuit film693. The panel printed circuit film 693 applies a driving signal todrive the display panel 690. The panel printed circuit film 693 iselectrically connected to an end portion of the first substrate 691.

The panel printed circuit film 693 is bent and surrounds the firstsidewall 613 along the first guiding groove that is formed on an outersurface of the first sidewall 613. A first terminal of the panel printedcircuit film 693 is electrically connected to a driving circuit member620. A second terminal of the panel printed circuit film 693 iselectrically connected to the electric power printed circuit film 670along a second guiding groove that is formed on the outer surface of thefirst sidewall 613.

The driving circuit member 620 applies the electric power to a firstlight-emitting diode 631 of the first backlight unit 630 and a secondlight-emitting diode 651 of the second backlight unit 650 in the mainmode. In addition, the driving circuit member 620 applies the electricpower to the second light-emitting diode 651 of the second backlightunit 650 in the sub mode. That is, in the sub mode, the second lightgenerated from the second light-emitting diode 651 is incident into thesub display part SDP of the display panel 690, and the first light isnot generated from the first light-emitting diode 631.

When the driving signal is applied to the display panel 690, an electricfield is formed between the first and second substrates 691 and 695.Liquid crystals of the liquid crystal layer 696 vary in arrangement inresponse to the electric field applied thereto, and a lighttransmittance of the first light generated from the first backlight unit630 to pass through the liquid crystal layer 696 or the second lightgenerated the liquid crystal layer 696 to pass through the liquidcrystal layer 696 is changed, thereby displaying image having apredetermined gray-scale.

The first backlight unit 630 includes a first light source 631 and afirst light guiding unit 633. The first light source 631 supplies thefirst light guiding unit 633 with the first light. The first lightguiding unit 633 guides the first light toward the main display part toincrease a luminance uniformity of the first light. The first lightguiding unit 633 may include a light guiding material having variouscharacteristics such as high light transmittance, high heat resistance,high chemical resistance, high mechanical strength, etc.

The first backlight unit 630 may further include first optical sheets638. The first optical sheets 638 improve optical characteristics of thefirst light exiting the first light guiding unit 633. The first opticalsheets 638 may include a first reflecting sheet 635, a first diffusionsheet 636 and/or a first brightness enhancement sheet 637.

The second backlight unit 650 includes a second light source 651 and asecond light guiding unit 653. The second light source 651 supplies thesecond light guiding unit 653 with the second light. The second lightguiding unit 653 guides the second light having increased luminanceuniformity toward the sub display part.

The second backlight unit 650 may further include second optical sheets658. The second optical sheets 658 improve optical characteristics suchas luminance uniformity, a luminance when viewed on a plane, etc., ofthe second light exiting the second light guiding unit 653. The secondoptical sheets 658 may include a second reflecting sheet 655, a seconddiffusion sheet 656 and/or a second brightness enhancement sheet 657.

A first recess (not shown) is formed on the first sidewall 613, and ahole (not shown) is formed through a peripheral portion of the bottomplate 611 corresponding to the first recess (not shown). A second recess616 is formed on the second sidewall 615, and a hole is formed through aperipheral portion of the bottom plate 611 corresponding to the secondrecess 616. In exemplary embodiments, first and second guiding groovesmay be formed on an outer surface of the first sidewall 613.

The light blocking member 612 is interposed between the first backlightunit 630 and the second backlight unit 650 to optically isolate thefirst backlight unit 630 from the second backlight unit 650.

The light blocking member 612 divides a receiving space of the receivingcontainer 610 into a main receiving region and a sub receiving region.The bottom plate 611, the light blocking member 612 and the first, thirdand fourth sidewalls 613, 617 and 619 define the main receiving region.The bottom plate 611, the light blocking member 612 and the second,third and fourth sidewalls 615, 617 and 619 define the sub receivingregion. The bottom plate 611 corresponding to the main receiving regionhas a first area. The bottom plate 611 corresponding to the subreceiving region has a second area that is smaller than the first area.FIG. 17 is an exploded perspective view illustrating another exemplaryembodiment of a display device in accordance with the present invention.

Referring to FIG. 17, the display device 700 includes a backlightassembly 705 and a display panel 790.

The backlight assembly 705 generates a first light in a main mode andgenerates a second light in a sub mode. The second light has a differentcolor from the first light. A driving method of the backlight assemblyof FIG. 17 is substantially the same as in FIGS. 7 to 9B, and thus anyfurther explanation concerning the above element will be omitted. Thebacklight assembly 705 includes a light source unit 710, a drivingcircuit member 720, a light guiding unit 730 and a receiving container770.

The light source unit 710 may further include an electric power printedcircuit film 719. The light source unit of FIG. 17 is substantially thesame as in FIG. 7 except for the electric power printed circuit film,and thus any further explanation concerning the above element will beomitted.

The electric power printed circuit film 719 may have a substantiallyL-shape. In FIG. 17, the electric power printed circuit film 719 mayfurther include an electric power transmitting line that is electricallyconnected to two first light-emitting diodes 711 and a secondlight-emitting diode 717. The electric power printed circuit film 719may be electrically connected to the electric power supplying part 720.The first light-emitting diodes 711 are on an upper portion of theL-shaped electric power printed circuit film 719. The secondlight-emitting diode 717 is on a lower portion of the L-shaped electricpower printed circuit film 719.

The driving circuit member 720 is electrically connected to the electricpower printed circuit film 719. The driving circuit member 720 appliesan electric power to the first light-emitting diodes 711 in the mainmode and applies the electric power to the second light-emitting diode717 in the sub mode. The driving circuit member 720 is electricallyconnected to the display panel 790.

FIG. 18 is a cross-sectional view illustrating the display panel takenalong line V-V′ shown in FIG. 17.

A receiving container of FIGS. 17 and 18 is substantially the same as inFIGS. 10 and 12 except for a partition wall, a first groove and a secondgroove. The receiving container of FIGS. 17 and 18 does not include thepartition wall shown in FIG. 10 and 12, and the receiving container ofFIGS. 17 and 18 includes two first grooves on a first sidewall of thereceiving container for receiving two first light emitting diodes andthe second groove on a fourth sidewall of the receiving container forreceiving the second light emitting diode. Thus, any further explanationconcerning the above elements will be omitted.

Referring to FIGS. 17 and 18, the light guiding unit 730 includes alight guiding plate 731 and optical sheets 741.

The light guiding plate of FIGS. 17 and 18 is substantially the same asin FIG. 7, and the optical sheets of FIGS. 17 and 18 are substantiallythe same as in FIG. 13. Thus, any further explanation concerning theabove elements will be omitted.

The optical sheets 741 include a reflecting sheet 743, a diffusion sheet745 and a brightness enhancement sheet 747. The reflecting sheet 743,the diffusion sheet 745 and the brightness enhancement sheet 747 arereceived on a bottom plate 771 of the receiving container 770, insequence.

The display panel 790 displays images based on the first and secondlights generated from the backlight assembly 705. The display panel 790includes a main display part MDP and a sub display part SDP.

The main display part MDP corresponds to a main region MD of a lightexiting surface 737 of the light guiding plate 731, and the sub displaypart SDP corresponds to a sub region SS that is a remaining area of thelight exiting surface 737 of the light guiding plate 731.

In a main mode, the display panel 790 displays main images on the maindisplay part MDP and does not display sub images on the sub display partSDP. In a sub mode, the display panel 790 displays the sub images on thesub display part SDP and does not display the main images on the maindisplay part MDP.

In the main mode, the first light generated from the firstlight-emitting diodes 711 of the backlight assembly 705 is incident intothe main display part MDP. The display panel 790 changes a color of thefirst light to display the main images on the main display part MDPbased on the first light generated from the first light-emitting diodes711. The main images may include a moving image, a character, etc.

In the sub mode, the second light generated from the secondlight-emitting diode 717 of the backlight assembly 705 is incident intothe sub display part SDP. The display panel 790 displays the sub imageson the sub display part SDP based on the second light generated from thesecond light-emitting diode 717. The display panel 790 may not change acolor of the second light to display the sub images. The sub images mayinclude a time, a data, a battery state, etc.

FIG. 19A is a cross-sectional view illustrating the display panel takenalong line V-V′ shown in FIG. 17 in a main mode. FIG. 19B is across-sectional view illustrating the display panel taken along lineV-V′ shown in FIG. 17 in a sub mode.

Referring to FIGS. 19A and 19B, the display panel 790 includes a firstsubstrate 791, a second substrate 795 and a liquid crystal layer 796.The first substrate 791 includes a lower substrate 781, a switchingelement 782 and a pixel electrode 784. Alternative exemplary embodimentsinclude configurations where the first substrate 791 may further includea plurality of switching elements and a plurality of pixel electrodes.

In one exemplary embodiment, the lower substrate 781 includes atransparent glass. A main pixel region and a sub pixel region aredefined in the lower substrate 781. The main pixel region issubstantially in parallel with the sub pixel region. A plurality ofpixel regions is defined in the main and sub pixel regions in a matrixshape.

The switching element 782 is on each of the pixel regions to apply amain image signal or a sub image signal to a pixel electrode 784 at apredetermined timing.

The switching element 782 includes a source electrode SE, a drainelectrode DE and a gate electrode GE. The main image signal or the subimage signal is applied to the source electrode. The main image signalor the sub image signal is outputted through the drain electrode DE. Theswitching element 782 is controlled by a gate signal applied to the gateelectrode GE.

The switching element 782 may further include a gate insulating layerand a semiconductor layer. The gate insulating layer covers the gateelectrode GE, so that the gate electrode GE is electrically insulatedfrom the source and drain electrodes SE and DE. The semiconductor layeris on the gate insulating layer corresponding to the gate electrode GE,and is partially overlapped with the source and drain electrodes SE andDE.

The first substrate 791 may further include a protecting layer 783. Theprotecting layer 783 is on the lower substrate 781 to cover theswitching element 782. A contact hole CT is formed on the protectinglayer 783. The drain electrode DE of the switching element 782 ispartially exposed through the contact hole CT.

The pixel electrode 784 includes a transparent conductive material. Thepixel electrode is on the protecting layer 783 corresponding to each ofthe pixel regions. The pixel electrode 784 is electrically connected tothe drain electrode DE through the contact hole CT. In exemplaryembodiments, the transparent conductive material that may be used forthe pixel electrode 784 are indium tin oxide (ITO), tin oxide (TO),indium zinc oxide (IZO), zinc oxide (ZO), amorphous indium tin oxide(a-ITO), indium tin-zinc oxide (ITZO), etc.

The second substrate 795 faces the first substrate 791. The secondsubstrate 795 includes an upper substrate 785, a black matrix 786, colorfilters 787 a, 787 b and 787 c and a common electrode 788.

The upper substrate 785 includes a transparent glass. A main colorregion and a sub color region are defined on the upper substrate 785.The main color region of the upper substrate 895 corresponds to the mainpixel region of the lower substrate 781. The sub color region of theupper substrate 785 corresponds to the sub pixel region of the lowersubstrate 781.

The upper and lower substrates 785 and 781 may not include alkalineions. When the upper and lower substrates 785 and 781 include thealkaline ions, the alkaline ions may be dissolved in the liquid crystallayer 796 and decrease a resistivity of liquid crystals of the liquidcrystal layer 796, thereby deteriorating image display quality. Inaddition, an adhesive strength between a sealant and the glass substrateis decreased. Furthermore, the switching element 782 may bemalfunctioned.

In exemplary embodiments, each of the upper and lower substrates 785 and781 may also include triacetylcellulose (TAC), polycarbonate (PC),polyethersulfone (PES), polyethyleneterephthalate (PET),polyethylenenaphthalate (PEN), polyvinylalcohol (PVA),polymethylmethacrylate (PMMA), cyclo-olefin polymer (COP), etc. Thesecan be used alone or in combination thereof.

In other exemplary embodiments, each of the upper and lower substrates785 and 781 may be optically isotropic.

The black matrix 786 blocks a portion of the light incident into aregion in which the liquid crystals are incontrollable. In particular,the black matrix 786 is between the unit pixel regions that are formedin the main pixel region and in the sub pixel region and arranged in amatrix shape on the upper substrate 785.

In exemplary embodiments, a metal composition, an opaque organicmaterial, etc., may be formed on the upper substrate 785 and partiallyremoved to form the black matrix 786. In one exemplary embodiment, themetal includes chromium. In another exemplary embodiment the metalcomposition may include chromium oxide, chromium nitride, etc. Inanother exemplary embodiments the opaque organic material may includecarbon black, a pigment mixture, a colorant mixture, etc. The pigmentmixture may include red, green and blue pigments. The colorant mixturemay include red, green and blue pigments. In another exemplaryembodiment, the metal or the metal composition is deposited on the uppersubstrate 785 and then partially etched to form the black matrix 786.

Alternative embodiments include configurations where a photoresist layerincluding the opaque organic material is coated on the upper substrate785 and then patterned through a photo process to form the black matrix786.

Each of the color filters 787 a, 787 b and 787 c transmits a color lighthaving a predetermined wavelength. In FIGS. 19A and 19B, the colorfilters 787 a, 787 b and 787 c may only be in the main color region. Inparticular, the color filters 787 a, 787 b and 787 c are in the regionsdefined by the black matrix 786. The color filters 787 a, 787 b and 787c may include a red color filter portion 787 a, a green color filterportion 787 b and a blue color filter portion 787 c. The red, green andblue color filter portions 787 a, 787 b and 787 c correspond to thepixel regions of the lower substrate 781, respectively.

Alternative embodiments include configurations where end portions of thered, green and blue color filter portions 787 a, 787 b and 787 c may bepartially overlapped to form the black matrix 786.

The color filters 787 a, 787 b and 787 c may include a photo initiator,a monomer, a binder, a colorant, a dispersing agent, a solvent, aphotoresist, etc. Alternatively, the color filters 787 a, 787 b and 787c corresponding to the main pixel region may be on a passivation layer723 that is on the lower substrate 781 to cover the switching element782.

In FIG. 19A, in the main mode, the first light passes through the redcolor filter portion 787 a, the green color filter portion 787 b or theblue color filter portion 787 c of the main display part MDP to converta white light into a red light, a green light or a blue light.

In FIG. 19B, in the sub mode, the color filters 787 a, 787 b and 787 care not formed on the sub display part SDP, so that the sub image isdisplayed on the sub display part SDP using the second light. The secondlight does not pass through the color filters 787 a, 787 b and 787 c,thereby increasing a luminance of the sub display part SDP.

The common electrode 788 is on an entire of the upper substrate 785having the black matrix 786 and the color filters 787 a, 787 b and 787c. In exemplary embodiments, the common electrode 788 may include atransparent conductive material. The transparent conductive material mayinclude indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO),zinc oxide (ZO), amorphous indium tin oxide (a-ITO), indium tin-zincoxide (ITZO), etc. Alternative embodiments include configurations wherethe common electrode 788 may be formed on the lower substrate 781 withthe pixel electrode 784.

In other exemplary embodiments, the display panel 790 may furtherinclude a spacer (not shown). The spacer (not shown) is formed on theupper substrate 785 having the black matrix 786, the color filters 787a, 787 b and 787 c and the common electrode 788. The first substrate 791is spaced apart from the second substrate 795 by a substantiallyconstant distance.

The liquid crystal layer 796 is interposed between the first and secondsubstrates 791 and 795 and sealed by the sealant (not shown). Inexemplary embodiments, the liquid crystal 796 may be aligned in atwisted nematic (TN) mode. In alternative exemplary embodiments, liquidcrystals of the liquid crystal layer 796 may be aligned in a verticallyaligned (VA) mode, a mixed twisted nematic (MTN) mode, a homogeneousmode, etc.

The first and second substrates 791 and 795 may further includealignment layers (not shown), respectively, to align the liquid crystallayer 796. In addition, the first substrate 791 may further include astorage capacitor (not shown).

The storage capacitor (not shown) is formed on the lower substrate 781to maintain a voltage difference between the common electrode 788 andthe pixel electrode 784.

The display panel 790 may further include a panel printed circuit film793. The panel printed circuit film 793 applies a driving signal to thedisplay panel 790. The panel printed circuit film 793 is electricallyconnected to an end portion of the first substrate 791.

The receiving container 770 may include first sidewall 773, secondsidewall 775, third sidewall 777 and fourth sidewall 779. The panelprinted circuit film 793 is bent and surrounds the first sidewall 773 ofthe receiving container 770 along a first guiding groove. A firstterminal of the panel printed circuit film 793 is electrically connectedto a driving circuit member 720. A second terminal of the panel printedcircuit film 793 is aligned along a second guiding groove of the firstsidewall 773 to be electrically connected to the electric power printedcircuit film 719.

When a voltage difference is applied to the pixel electrode 784 and thecommon electrode 788, an electric field is formed between the pixelelectrode 784 and the common electrode 788. Liquid crystals of theliquid crystal layer 796 vary arrangements in response to the electricfield applied thereto.

Therefore, a light transmittance of the liquid crystal layer 796corresponding to the main display part MDP or the sub display part SDPis changed, so that the display panel 790 displays images.

Particularly, in the main mode, the display panel 790 controls the lighttransmittance of the first light that is the white light using theliquid crystal layer 796 in the main display part MDP. The color filters787 a, 787 b and 787 c that are on the main display part MDP change acolor of the first light, thereby displaying main images on the maindisplay part MDP.

In the sub mode, the display panel 790 controls the light transmittanceof the second light that is one of the red, green and blue lights usingthe liquid crystal layer 796 in the sub display part SDP. The colorfilters 787 a, 787 b and 787 c are not on the sub display part MDP, sothat a color of the second light is not changed, thereby displaying subimages on the sub display part MDP.

FIG. 20 is an exploded perspective view illustrating another exemplaryembodiment of a display device in accordance with the present invention.

Referring to FIG. 20, the display device 900 includes a backlightassembly 905 and a display panel 990.

The backlight assembly of FIG. 20 has substantially the same as in FIGS.10 to 12 except for a light source unit and a receiving container, andthus any further explanation concerning the above elements will beomitted.

The light source unit of FIG. 20 has substantially the same as in FIG.17 except for an operation, and thus any further explanation concerningthe above elements will be omitted. The light source unit of FIG. 20 isoperated through a substantially same method as in FIGS. 10 to 12. Firstlight-emitting diodes 911 generate a white light in a main mode and donot generate the white light in a sub mode. A second light-emittingdiode 917 generates one of the red, green and blue lights in the mainmode and the sub mode. Therefore, the display device 900 displays a subimage in the main mode and the sub mode.

The backlight assembly 905 includes a light source unit 910, a drivingcircuit member 920, a light guiding unit 930 and a receiving container970. The display panel 990 includes a first substrate 991, a secondsubstrate 995 and a liquid crystal layer 996.

The light guiding unit 930 includes a main light guiding plate 931 a sublight guiding plate 935 and optical sheets. The main light guiding plate931 is received in a main receiving region of the receiving container970 and the sub light guiding plate 935 is received in a sub receivingregion of the receiving container 970. The main light guiding plate 931is substantially in parallel with the sub light guiding plate 935.

The main light guiding plate 931 guides the first light that is incidentinto the main light guiding plate 931 through a side surface facing thefirst sidewall 973 toward an upper portion of the backlight assembly905. The sub light guiding plate 935 guides the second light that isincident into the sub light guiding plate 935 through a side surfacefacing the second sidewall 975 toward the upper portion of the backlightassembly 905.

The partition wall 972 is interposed between the main light guidingplate 931 and the sub light guiding plate 935, so that the main lightguiding plate 931 is optically isolated from the sub light guiding plate935.

The optical sheets include main optical sheets 941 and sub opticalsheets 951. The main optical sheets 941 improve optical characteristicsof the first light exiting the main light guiding plate 931. The mainoptical sheets 941 include a main reflecting sheet 943, a main diffusionsheet 945 and a main brightness enhancement sheet 947. The sub opticalsheets 951 improve optical characteristics of the second light exitingthe sub light guiding plate 951. The sub optical sheets 951 include asub reflecting sheet 953, a sub diffusion sheet 955 and a sub brightnessenhancement sheet 957.

Two first recesses (not shown) are formed on the first sidewall 973 ofthe receiving container 970, and two holes (not shown) are formedthrough a peripheral portion of a bottom plate 971 of the receivingcontainer 970 corresponding to the first recesses (not shown). A secondrecess (not shown) is formed on a second sidewall 975, and a hole isformed through a peripheral portion of the bottom plate 971corresponding to the second recess (not shown). The receiving containerof FIG. 20 is substantially the same as in FIGS. 10 to 12 except thefirst recesses and the holes. The first light-emitting diodes 911 arereceived in the first recesses (not shown) of the first sidewall 973through the holes (not shown) of the bottom plate 971 corresponding tothe first recesses (not shown), respectively. The second light-emittingdiode 917 is received in the second recess (not shown) of the secondsidewall 975 through the hole of the bottom plate 971 corresponding tothe second recess (not shown).

The receiving container 970 may include first sidewall 973, secondsidewall 975, third sidewall 977 and fourth sidewall 979. The panelprinted circuit film 993 is bent and surrounds the first sidewall 973 ofthe receiving container 970 along a first guiding groove. A firstterminal of the panel printed circuit film 993 is electrically connectedto a driving circuit member 920. A second terminal of the panel printedcircuit film 993 is aligned along a second guiding groove of the firstsidewall 973 to be electrically connected to the electric power printedcircuit film 919.

The receiving container 970 may further include a partition wall 972between the sub display part SDP and the main display part MDP, so thatthe sub display part SDP is optically isolated from the main displaypart MDP. The display panel 990 of FIG. 20 is substantially the same asin FIGS. 17 to 19B, and thus any further explanation concerning theabove elements will be omitted.

FIG. 21 is a plan view illustrating an exemplary embodiment of a displaysubstrate in accordance with the present invention. FIG. 22 is anenlarged plan view illustrating portion ‘A’ shown in FIG. 21.

Referring to FIGS. 21 and 22, the display substrate 1100 includes a basesubstrate 1105, a switching element 1140 and a reflecting plate 1180. Inalternative exemplary embodiments, the display substrate 1100 mayfurther include a plurality of switching elements. The display substrate1100 may be used for a display device having a main display part and asub display part.

The base substrate 1105 may include a transparent glass substrate. Thebase substrate 1105 includes a main driving region 1110 corresponding tothe main display part and a sub driving region 1120 corresponding to thesub display part. The main driving region 1110 is substantially inparallel with the sub driving region 1120 to divide the base substrate1105. A plurality of pixel regions 1111 and 1121 are in the main drivingregion 1110 and the sub driving region 1120 in a substantially matrixshape.

FIG. 23 is a cross-sectional view taken along line VI-VI′ shown in FIG.22.

Referring to FIGS. 21 to 23, the switching element 1140 is on the basesubstrate 1105 and applies an externally provided data signal to atransparent electrode 1170.

The switching element 1140 includes a gate electrode GE electricallyconnected to a gate line GL, a gate insulating layer 1130, a channelpattern CP, a source electrode SE electrically connected to a data lineDL and drain electrode DE. The display substrate 1100 may furtherinclude a plurality of switching elements, a plurality of gate lines anda plurality of data lines.

The gate lines GL are extended in a first direction. The gate lines GLin the main driving region 1110 are spaced apart from each other by afirst distance. The gate lines GL in the sub driving region 1120 arespaced apart from each other by a second distance that is greater thanthe first distance. The gate electrode GE is protruded from one of thegate lines GL in a second direction that is substantially inperpendicular to the first direction.

The gate insulating layer 1130 covers the gate electrode GE and the gatelines GL, so that the gate electrode GE and the gate lines GL areelectrically insulated from the source electrode SE and the data linesDL. In one exemplary embodiment, the gate insulating layer 1130 may be asilicon nitride layer.

The channel pattern CP is on the gate insulating layer 1130corresponding to the gate electrode GE. The channel pattern CP mayinclude an amorphous silicon pattern ASP and an N+ amorphous siliconpattern nASP. In FIG. 23, two N+ amorphous silicon patterns nASP thatare spaced apart from each other are on the amorphous silicon patternASP.

The data lines DL are on the gate insulating layer 1130. The data linesDL are extended in the second direction and are substantially inparallel with each other. The pixel regions 1111 and 1121 are defined bythe gate and data lines GL and DL adjacent to each other.

The data lines DL are spaced apart from each other by a third distancein the main driving region 1110. Every three data lines DL adjacent toeach other in the sub driving region 1120 form a plurality of a dataline assembly in the sub driving region 1120. That is, each of the dataline assembly includes the three data lines DL adjacent to each other.The data line assemblies are spaced apart from each other by a fourthdistance in the sub driving region 1120. Therefore, the pixel regions1121 in the sub driving region 1120 have a greater area than the pixelregions 1111 in the main driving region 1110, so that the main drivingregion 1110 has a greater resolution than the sub driving region 1120.

The source electrode SE is protruded from one of the data lines DL in afirst direction. The source electrode SE is on one of the N+ amorphoussilicon pattern to be electrically connected to the one of the N+amorphous silicon pattern.

The drain electrode DE is on another of the N+ amorphous silicon patternto be electrically connected to the another of the N+ amorphous siliconpattern. The drain electrode DE may be formed from a substantially thesame layer as the data lines DL.

FIG. 24 is an enlarged plan view illustrating portion ‘B’ shown in FIG.21. FIG. 25 is a cross-sectional view taken along line VII-VII′ shown inFIG. 24.

Referring to FIGS. 21 to 25, the display substrate 1100 may furtherinclude an insulating pattern 1150 and a transparent electrode 1170.

The insulating pattern 1150 is on the base substrate 1105 to cover theswitching element 1140. The insulating pattern 1150 includes a contacthole CT through which the drain electrode DE of the switching element1140 is partially exposed. In one exemplary embodiment, the insulatingpattern 1150 may include a photoresist material for forming the contacthole CT.

An embossing pattern 1155 may be formed on an upper surface of theinsulating pattern 1150 in the sub driving region 1120. The uppersurface of the insulating pattern 1150 in the main driving region 1110may have a substantially flat shape.

The transparent electrode 1170 includes a transparent conductivematerial. The transparent electrode 1170 corresponds to each of thepixel regions. The transparent electrode 1170 is electrically connectedto the drain electrode DE through the contact hole CT of the insulatingpattern 1150. In exemplary embodiments, transparent conductive materialthat can be used for the transparent electrode 1170 may include indiumtin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), zinc oxide(ZO), amorphous indium tin oxide (a-ITO), indium tin zinc oxide (ITZO),etc.

The reflecting plate 1180 includes a highly reflective material. Inexemplary embodiments, the highly reflective material that can be usedfor the reflecting plate 1180 may include aluminum, niobium, etc. InFIGS. 21 to 25, the reflecting plate 1180 is in each of the pixelregions of the sub driving region 1120.

The reflecting plate 1180 is on the transparent electrode 1170, andelectrically connected to the transparent electrode 1170 to form thereflection electrode. The reflecting plate 1180 is on the embossedpattern 1155 that is formed on the insulating pattern 1150 in the subdriving region. The reflecting plate 1180 is on the embossing pattern1155 to increase a luminance when viewed on a plane.

The reflecting plate 1180 has an opening on a central portion of thereflecting plate 1180 to divide each of the pixel regions 1121 into areflection portion 1181 and a transmission portion 1183. An externallyprovided light is reflected from the reflecting plate 1180 of thereflection portion 1181. An internally provided light may pass throughthe transmission portion 1183. In FIGS. 21 to 25, the transmissionportion 1183 is on a central portion of each of the pixel regions 1121.Alternative exemplary embodiments include configurations where thelocation of the transmission portion 1183 may be changed. In oneexemplary embodiment, the transmission portion 1183 may be on a cornerof each of the pixel regions 1121.

In FIGS. 21 to 25, in the main driving region 1110, the reflecting plate1180 is not formed on the transmission electrode 1170 and thetransmission electrode 1170 is in each of the pixel regions 1111.

Referring again to FIGS. 23 and 25, the display substrate 1100 mayfurther include an alignment layer 1190. The alignment layer 1190 isdisposed on the transmission electrode 1170 and the reflecting plate1180. In exemplary embodiments, the alignment layer 1190 includes apolyimide resin. A plurality of alignment grooves may be formed on thealignment layer 1190 to align the liquid crystals of the liquid crystallayer.

FIG. 26 is a plan view illustrating another exemplary embodiment of adisplay substrate in accordance with the present invention.

The display device of FIG. 26 is substantially the same as in FIGS. 21to 25 except for an insulating pattern and a reflecting plate. Thus, anyfurther explanation concerning the above elements will be omitted.

Referring to FIG. 26, the display device 1300 includes a base substrate1305, a switching element 1340, an insulating pattern 1350, atransparent electrode 1370, a reflecting plate 1380 and an alignmentlayer 1390. Alternative exemplary embodiments include configurationswhere the display 1300 further includes a plurality of switchingelements 1340, a plurality of transparent electrodes 1370 and aplurality of reflecting plates 1380.

The insulating pattern 1350 is on the base substrate 1305 having theswitching element 1340. An embossing pattern 1355 is formed on theinsulating pattern 1350 corresponding to pixel regions 1311 in a maindriving region 1310 and pixel regions 1321 in a sub driving region 1320.

The reflecting plate 1380 is on each of the pixel regions 1311 and 1321.Each of the pixel regions 1311 in the main driving region 1310 isdivided into a reflection portion 1385 and a transmission region 1387.Each of the pixel regions 1321 in the sub driving region 1320 is dividedinto a reflection portion 1381 and a transmission region 1383.Therefore, each of the main driving region 1310 and the sub drivingregion 1320 is considered including a reflective-transmissive mode.

FIGS. 27 to 29 are cross-sectional views illustrating an exemplaryembodiment of a method of manufacturing an array substrate in accordancewith the present invention.

The display substrate of FIGS. 27 to 29 is substantially the same as inFIGS. 21 to 25. Thus, the same reference numerals will be used to referto the same or like parts as those described in FIGS. 21 to 25 and anyfurther explanation concerning the above elements will be omitted.

Referring to FIG. 27, in order to manufacture the display substrate1100, a switching element 1140 is formed on a base substrate 1105 havinga main driving region 1110 and a sub driving region 1120.

In one exemplary embodiment, the switching element 1140 is manufacturedby a gate metal layer being formed on the base substrate 1105 through achemical vapor deposition (CVD) process and a sputtering process. Thegate metal layer is patterned to form a gate line GL and a gateelectrode GE that is electrically connected to the gate line GL.

A gate insulating layer 1130 is formed on the base substrate 1105 havingthe gate line GL and the gate electrode GE through a CVD process. In oneexemplary embodiment, the gate insulating layer 1130 may include siliconnitride.

An amorphous silicon layer, an N+ amorphous silicon layer and asource/drain layer are formed on the gate insulating layer 1130, insequence. In one exemplary embodiment, impurities are implanted in anupper portion of the amorphous silicon layer at a high concentration toform the N+ amorphous silicon layer.

The source/drain layer is patterned to form a source electrode SE, adata line DL and a drain electrode DE. The source electrode SE iselectrically connected to the data line DL. The drain electrode DE isspaced apart from the source electrode SE.

The amorphous silicon layer and the N+ amorphous silicon layer arepatterned using the source electrode SE, the data line DL and the drainelectrode DE as an etching mask to form an N+ amorphous silicon patternsnASP and an amorphous silicon pattern ASP, thereby forming a channelpattern CP having the N+ amorphous silicon patterns nASP and theamorphous silicon pattern ASP.

FIG. 28 is a cross-sectional view illustrating an exemplary embodimentof a display substrate in a main driving region. FIG. 28 is across-sectional view illustrating an exemplary embodiment of a displaysubstrate in a sub driving region.

Referring to FIGS. 28 and 29, a protecting layer is formed on the basesubstrate 1105 having the channel pattern CP, the source electrode SE,the data line DL and the drain electrode DE. The protecting layer mayinclude a photoresist layer having an organic material. The protectinglayer is patterned to form a contact hole CT, thereby forming aninsulating pattern 1150.

The contact hole CT is formed in the insulating pattern 1150. The drainelectrode DE of the switching element 1140 is partially exposed throughthe contact hole CT. In FIG. 28, an upper surface of the insulatingpattern 1150 in the main driving region 1110 may have a substantiallyflat shape. In FIG. 29, an upper surface of the insulating pattern 1150in the sub driving region 1120 may have an embossed pattern 1155.

A transparent conductive layer is formed on an entire of the insulatingpattern 1150 of the main and sub driving regions 1110 and 1120. A highlyreflective layer having a highly reflective metal or a highly reflectivealloy is deposited on the transparent conductive layer in the subdriving region 1120. Exemplary embodiments of the highly reflectivemetal that can be used for the highly reflective layer include aluminum,neodymium, etc. Alternative exemplary embodiments include thetransparent conductive layer that may be formed on the highly reflectivelayer having the aluminum.

The transparent conductive layer and the highly reflective layer thatare on the insulating pattern 1150 are patterned to form a transparentelectrode 1170 and a reflecting plate 1180. The transparent electrode1170 is electrically connected to the drain electrode DE. The reflectingplate divides each of pixel regions in the sub driving region 1120 intoa reflection portion 1181 and a transmission portion 1183.

FIG. 30 is a cross-sectional view illustrating another exemplaryembodiment of a display device in accordance with the present invention.

Referring to FIG. 30, the display device 1800 includes a displaysubstrate 1500, an opposite substrate 1600 and a liquid crystal layer1700.

The display device 1800 includes a main display part MDP and a subdisplay part SDP. The main and sub display parts MDP and SDP displaymain images and sub images in a main mode, respectively. The sub displaypart SDP displays the sub images in a sub mode. The main images mayinclude a moving image, a character, etc. The sub display part SDPdisplays the sub images using an externally provided light and/or aninternally provided light. When the externally provided light is notsufficient, the sub display part SDP displays the sub images using theinternally provided light. When the externally provided light issufficient, the sub display part SDP displays the sub images using theexternally provided light. The sub images may include a time, a data, abattery state, etc.

The display substrate 1500 includes a first substrate 1505, a switchingelement 1540, an insulating pattern 1550, a transparent electrode 1570,a reflecting plate 1580 and a first alignment layer 1590. An uppersurface of the insulating pattern 1550 in the main driving region MDPmay have a substantially flat shape. An upper surface of the insulatingpattern 1550 in the sub driving region SDP may have an embossed pattern1555.

The first substrate 1505 includes a main driving region corresponding tothe main display part MDP and a sub driving region corresponding to thesub display part SDP. The display substrate of FIG. 30 is substantiallythe same as in FIGS. 1 to 5, and thus any further explanation concerningthe above elements will be omitted.

The opposite substrate 1600 faces the display substrate 1500. Theopposite substrate 1600 includes a second substrate 1605, a color filter1610, a common electrode 1620 and a second alignment layer 1630.

The color filter 1610 is on the second substrate 1605. The color filter1610 corresponds to pixel regions of the display substrate, such aspixel regions 111 and 1121 of display substrate 1100 in FIG. 21. Thecolor filter 1610 includes a main color filter 1611 and a sub colorfilter 1615. In an exemplary embodiment, the main color filter 1611corresponds to pixel regions 1111 in the main driving region (See, FIG.21). The sub color filter 1615 corresponds to pixel regions 1121 in thesub driving region (See, FIG. 21). The color filter 1610 may include,but is not limited to, red, green and blue color filters that transmitred, green and blue lights, respectively.

The common electrode 1620 covers the color filter 1610. The commonelectrode 1620 may include a transparent conductive material. Inexemplary embodiments, the transparent conductive material that can beused for the common electrode 1620 include, but are not limited to,indium tin oxide (ITO), tin oxide (TO), indium zinc oxide (IZO), zincoxide (ZO), amorphous indium tin oxide (a-ITO), indium tin-zinc oxide(ITZO), etc. The common electrode 1620, the transparent electrode 1570of the display substrate 1500 and the liquid crystal layer 1700 form aliquid crystal capacitor. The common electrode 1620, the reflectingplate 1580 of the display substrate 1500 and the liquid crystal layer1700 may also form a liquid crystal capacitor.

The second alignment layer 1630 covers the common electrode 1620 andincludes a plurality of alignment grooves (not shown) for aligningliquid crystals of the liquid crystal layer 1700.

The liquid crystal layer 1700 is interposed between the displaysubstrate 1500 and the opposite substrate 1600.

In an exemplary embodiment, the light source supplies the main and subdisplay parts with different lights, so that the main and sub displayparts may be independently operated. Advantageously, a power consumptionof the display device is smaller than that of a display device having abacklight assembly including a light source supplying a light on anentire of a light incident surface of a display panel.

In another exemplary embodiment, the sub display part has a smaller areathan the main display part, and the light generated from the lightsource adjacent to the sub display part is guided toward only the subdisplay part in the sub mode. Advantageously, the luminance of the subdisplay part is increased, although the amount of the electric powerapplied to the light source adjacent to the sub display part isdecreased.

In another exemplary embodiment, the main display part displays mainimages based on the white light and the sub display part displays subimages based on one of the red, green and blue lights. Advantageously,one of the red, green and blue lights may not be blocked by the colorfilter in the sub display part, so that the luminance of the sub displaypart is increased, and an image display quality of the sub image isimproved.

In another exemplary embodiment, the display substrate includes the maindriving region and the sub driving region, and the reflecting plate isformed in the sub driving region, so that each of the pixel regions ofthe sub driving region includes the reflection portion and thetransmission portion. Advantageously, the luminance of the sub displaypart is increased in the sub mode, thereby improving image displayquality.

This invention has been described with reference to the exampleembodiments. It is evident, however, that many alternative modificationsand variations will be apparent to those having skill in the art inlight of the foregoing description. Accordingly, the present inventionembraces all such alternative modifications and variations as fallwithin the spirit and scope of the appended claims.

1. A backlight assembly comprising: a light source unit comprising: afirst light source generating a first light; and a second light sourcegenerating a second light having a different color from the first light;a light guiding unit guiding the first and second lights generated fromthe light source unit; and a power supplying part applying power to thefirst and second light sources; wherein the power supplying part appliesthe power to the first light source in a main mode, and applies thepower to the second light source in a sub mode.
 2. The backlightassembly of claim 1, wherein the first light source comprises a firstlight-emitting diode generating a white light, and the second lightsource comprises a second light-emitting diode generating one of red,green and blue lights.
 3. The backlight assembly of claim 1, furthercomprising: a receiving container receiving the light source unit andthe light guiding unit.
 4. The backlight assembly of claim 3, whereinthe light guiding unit comprises: a light guiding plate on a bottomplate of the receiving container; and optical sheets on the lightguiding plate, the optical sheets increasing a luminance when viewed ona plane and a luminance uniformity of a light exiting the light guidingplate.
 5. The backlight assembly of claim 4, wherein the first lightsource is on a substantially same surface of the light guiding plate asthe second light source.
 6. The backlight assembly of claim 4, whereinthe light guiding plate comprises: a first side surface adjacent to thefirst light source; and a second side surface adjacent to the secondlight source, the second side surface facing the first side surface. 7.The backlight assembly of claim 3, wherein the light guiding unitcomprises: a main light guiding plate adjacent to the first light sourceguiding the first light; a sub light guiding plate adjacent to thesecond light source guiding the second light; and optical sheets on themain and sub light guiding plates.
 8. The backlight assembly of claim 7,wherein the receiving container comprises: a bottom plate; and apartition wall protruded from the bottom plate between the main and sublight guiding plates.
 9. The backlight assembly of claim 7, wherein theoptical sheets comprises: main optical sheets on the main light guidingplate; and sub optical sheets on the sub light guiding plate.
 10. Abacklight assembly comprising, a light source unit comprising: a firstlight source generating a first light; and a second light sourcegenerating a second light having a different color from the first light;a light guiding unit guiding the first and second lights generated fromthe light source unit; and a power supplying part applying power to thefirst and second light sources; wherein the power supplying part appliesthe power to the first and second light sources in a main mode, andapplies the power to the second light source in a sub mode.